a. Field of the Invention
The instant invention relates to a bale press for baling a wide variety of materials and to a method of compressing a wide variety of materials into bales. In particular, the instant invention relates to bale presses and related methods for making cylindrical bales.
b. Background Art
It is well known that refuse may be compressed into bales, such as for transport, to burn for energy generation, or for disposal. Thus, the bales allow the refuse to be held together and to maintain its caloric value until the refuse is burned. In U.S. Pat. No. 6,336,306 (the '306 patent), for example, a round bale press or baler is disclosed including an endless belt guided around a plurality of deflection rollers via a pair of disk-like side walls or end plates defining a compression chamber. Refuse is fed into the compression chamber via a feed aperture and compacted into a round bale. A yarn or net web is unwound around a roller and into the compression chamber to pre-secure the compressed bale. The pre-secured bale may then be delivered to a wrapping apparatus to be fully enveloped in film, or the pre-secured bale may then be transported, burned, or otherwise disposed of as is. The endless belt comprises a segment pivotable out of a closed configuration suitable for compacting refuse to an open configuration suitable for discharging the pre-secured round bale from the compression chamber and conveying the bale to a wrapping table.
For some applications, the baling process is most cost-effective when the bales are, for example, efficiently and rapidly compacted to a high density. Where the bales are to be disposed of in a landfill, for example, it is valuable to maximize use of the available landfill volume by more tightly compacting each bale so as to increase the amount of refuse that can be stored in the same volume of the landfill. In addition, the less time it takes to produce each bale, the faster, more efficient, and cost-effective the waste disposal process becomes.
While round bale presses such as the one disclosed in the '306 patent provide round bales of compacted refuse that may be transported, burned, or otherwise disposed of, problems often arise when the bales are compacted at increased compression and/or higher speeds. Where the compression of the refuse in the compression chamber of a round bale press is increased, for example, refuse often “boils” at the feed aperture or “throat” of the compression chamber as the hard-packed bale in the compression chamber prevents the new refuse from entering the compression chamber. In addition, as bale compression increases in existing bale presses, the bale itself may bulge out at the feed aperture of the compression chamber. Before desirable bale densities can be reached, the bulge can get large enough that the bale is prevented from easily rotating within the compression chamber, and the motors driving the endless belt may stall or fail prematurely. Merely increasing the size or horsepower of the drive motor or motors may not overcome this stalling tendency and may unnecessarily increase the size and/or cost of the bale press.
Where the production speed of the bale press is increased, other problems are often created. For example, until enough refuse is in the compression chamber, the refuse rolls or tumbles around the chamber, similar to clothing in a dryer, without being compressed. Thus, wasted time and energy is used operating the bale press until the chamber is sufficiently full so that the refuse starts to be compacted. In addition, as the speed of the bale press is increased, the tendency of the yarn or net web to skew to one end of the roller may increase. A skewed web may, for example, insufficiently secure the bale so that as the bale exits the bale press, the bale falls apart and the bale press must be stopped to clean up the refuse that has separated from the bale. The skewed web may also catch on a portion of the compression chamber and jam the bale press. Again, the bale press must be stopped to clear the jam and realign the web. Time lost cleaning a busted bale from the bale press and realigning the web is time that could have been used to form more bales.
Further, as the pivotable segment of the endless belt opens, the kinetic energy of the bale may cause unloading problems if the bale is allowed to roll out of the compression chamber of the bale press.
Thus, it remains desirable to have a bale press that operates at high speed while creating high-density bales that may be efficiently unloaded from the bale press.